Transistor is an element commonly used in the current integrated circuit, and a CMOS (Complementary Metal-Oxide-Semiconductor) transistor is a complementary type of MOS transistor composed of a N channel transistor and a P channel transistor.
In order to address the short channel effect in a bulk silicon CMOS transistor, it has been proposed to apply Ultra thin SOI (Semiconductor on Insulator) in the future VLSI technology. However, an ultra thin SOI blanket wafer is expensive.
To avoid influences among transistors during operation, it is required to isolate transistors. The conventional isolation technology comprises STI (Shallow Trench Isolation), LOCOS (Local Oxidation of Silicon), SWAMI (Sidewall Masked Isolation), or the like. However, a relatively large area is required in the conventional technology to isolate the N channel transistor and P channel transistor and isolate the source, drain, and gate contacts of transistors. The fabricating cost is inevitably increased.